Fabrication of electronic circuit elements using metal nanoparticle liquid deposition techniques is of profound interest as such techniques provide potentially low-cost alternatives to conventional mainstream amorphous silicon technologies for electronic applications such as thin-film transistors (TFTs), light-emitting diodes (LEDs), RFID tags, photovoltaics. However, the deposition and/or patterning of functional electrodes, pixel pads, and conductive traces, lines and tracks which meet the conductivity, processing, and cost requirements for practical applications have been a great challenge.
Furthermore, phase change inks (sometimes referred to as “hot melt inks”) have also been used in various liquid deposition techniques. Phase change inks often contain a “phase change agent” that enables the ink to exist in a solid phase at ambient temperatures, but also exist in the liquid phase at the elevated operating temperature of an ink jet printing device. At the deposit operating temperature, droplets of liquid ink are ejected from the printing device and, when the ink droplets contact the surface of the recording substrate, either directly or via an intermediate heated transfer belt or drum, they quickly solidify to form a predetermined pattern of solidified ink drops. Phase change inks have also been used in other printing technologies, such as gravure printing, as disclosed in, for example, U.S. Pat. No. 5,496,879 and German Patent Publications DE 4205636AL and DE 4205713AL, the disclosures of each of which are totally incorporated herein by reference.
Phase change inks are desirable for ink jet printers because they remain in a solid phase at room temperature during shipping, long term storage, and the like. In addition, the problems associated with nozzle clogging as a result of ink evaporation with liquid ink jet inks are largely eliminated, thereby improving the reliability of the ink jet printing. Further, in phase change ink jet printers wherein the ink droplets are applied directly onto the final recording substrate (for example, paper, transparency material, and the like), the droplets solidify immediately upon contact with the substrate, so that migration of ink along the printing medium is prevented and dot quality is improved.
U.S. Patent Application Pub. No. 2007/0283846, which is incorporated herein by reference in its entirety, discloses a non-conductive organic phase change carrier comprising a colloidal dispersion of nanoparticles in a polar curable monomer, a phase-change inducing component and an initiator. In one embodiment, the nanoparticles are at least one of silicon nanoparticles and metal oxide nanoparticles. Upon exposure to UV light and/or heat, a solid is obtained and there is none of the component can be evaporated if heated.
U.S. Patent Application Pub. No. 2007/0119340, which is incorporated herein by reference in its entirety, discloses an ink carrier comprised of a colloidal dispersion of at least one of silica nanoparticles and metal oxide nanoparticles, the ink carrier further including a low melting wax and a gellant, wherein gel formation occurs at a temperature above the crystallization temperature of the wax. The ink described does not contain any liquid vehicle or solvent.